The IRS did not have an immediate explanation for the failure. But it said on its website that its online payment system became unavailable at 2:50 A.M. ET on Tuesday.

IRS Acting Commissioner David Kautter testified during a House Oversight Hearing Tuesday that a number of systems are down at the moment and that they are working to resolve the issue. (And Twitter reported outages worldwide if that offers the IRS any comfort.)

The IRS and U.S. Postal service have some tips for those of you trying to make the midnight deadline today. While traditional post offices will close at regular hours, processing centers in four counties will stay open until midnight.

If you’re really in a jam, file an extension today (but don’t forget to pay your bill, if you owe money to the state or federal government).